The immediate goal of this project is the design of self-replicating and self-assembling transmembrane peptide nanotube ion channels. The approach is to effect an autocatalytic cyclization of linear peptide precursor at the interface of Iipid bilayers. Autocatalytic peptide cyclization is thought to be directed by specific molecular recognition events occurring through backbone-backbone hydrogen bonding and side chain - side chain it- interactions between the linear pep tide and the cyclic peptide template residing at the lipid-water interface. Peptide cyclization is followed by its spontaneous self-assembly in the lipid bilayers to produce transmembrane ion channels. Such channels are known to effect size- selective transport of ions and/or small molecules across lipid bilayers. The long-range goal of this proposal is to gain insights into the mechanism of drug delivery methods and the formation of site specific channels via molecular recognition on membrane surface. This method could potentially be useful as a selective delivery method of drugs to specific cells types.